What an education a newbie to Mac can get out of this web site. When visiting the Mac Store here in Hawaii, they were very helpful in assisting me in picking out what I need. I definitely want the 17" and they suggest the Time Capsule (500GB) for $300. I have an up and working wireless PC network (Linksis). From what I read here, I can purchase a non-apple external HD that will work with Time Machine for a much lower price than $300 and can use my existing wireless network. Is my understanding correct? Any suggestions? Thank you.